PyQt5 - 在 QlineEdit 上检测 DeleteKey

Question

I would like to know the easiest way to detect when I delete text (with protentially Qt.Key_Delete ) from a QlineEdit?

The goal is that I can delete text from all 3 QLEdit when I use the Delete key of a single QLEdit

Thanks

Answer 1

The whole objective is this: I have 3LineEdit : Frequency Min , Frequency Max and Frequency Span . When I write in one of the 3 fields, it should automatically change the value of all other fields because: Frequency Min = Frequency Span - Frequency Max . //// Frequency Max = Frequency Span + Frequency Min //// Frequency Span = Frequency Max - Frequency Min ////. It doesn't really work but I'm close. I'm only testing with the Frequency Min modification . This is new for me. My current concern is that when I delete Frequency Min, I would like it to **delete text in QLE Frequency Span and Frequency Max **.

But, they keep their value so it distorts the result if I rewrite in Frequency Min. So I would like to delete both when my program detects that I am deleting text in the Frequency Min QLineEdit . Then I would make this case with the other data